Rotary jar



April 24, 1951 w. H. DUMLE ROTARY JAR Filed Dec. 9, 1947 INVENTOR, 77: llzm 7!: 22(7); 328;

Patented Apr. 24, 1951 "ZUNITED STATES PATENT" ormciz ROTARY JAR- William H. Dumble, Bakersfield; Calif. Application December 9, 1947-, Serial No. 790,637

' 4 claims. (01. 255-27?) v This invention is an assembly of the type known in the oil field industry as a jar.

in awell hole that it cannot be pulled without danger of damage to or loss of the tool and a part, at least of the made-up string of pipe sections and drill collar, which latter is at the lower end of the working string.

Many kinds of torque controlled jars assemblies have been proposed and several are quite Successful; but there is always some chance of jar failure for various reasons well known in the art; especially so when the ping elements have at least one rigid with the conventional jar housing.

It is an object of this invention to provide a jar in which the tripping device is more ultimate trip of housing from the frozen man- Also, an object of the invention is to provide a spring controlled tripping jar in which there is for varying the reaction principles of the invention as it is claimed in conclusion hereof.

of the hammer. Figure 2 is a cross section of the housing on line 22 of Fig. 1. Figure 3 is a cross-section on line 3-3, Fig '1 Figure 4 is a cross-section of the trip sleeve, on line 4-4 of Fig. 1. Figure 5 is a cross-section of the upper part of the mandrel; its locking lugs being in plan.

2 The housing of this jar includes an elongate, tubular shell 2 to the lower end of. which is 2b in the lower end of which is threaded a bushing 3 whose top end constitutes a hammer H. Slidably fitted in the bore of the barrel is a mandrel 4 on which is screwed a coupling 5 for attachment of'any desired subjacent tool or other tool string device (not shown). The mandrel has longitudinal shell 2, Torque herein means rotational effort. The mandrel has an anvil forming shoulder A to be impinged by the hammer H when this is given a sudden upward stroke, as will be explained.

To the mandrel 4 is coaxially screwed a manon the top, sleeve supporting end of the barrel 2?).

To facilitate the washing out of small solid grains of sand orother pieces the sleeve has wash windows W to its bore. For the purpose of lockiablyjfit on the upper end of for a repeat tripping tool string-when this jar is made up in such a string.

Means are provided to restrain the tripping action of the trip sleeve until a desired tool string tension has been set up in the jar by way of the mandrel lugs 4a: locking in the sleeve teeth 12. To that purpose the upper end of the sleeve H! has an oblique torque face l5 constantly engaged by 16 on the lower end of the condog 9 which is slidably splined at 8 on the upper end of the mandrel core 40.

The dog is constantly pressed down onto the sleeve by a strong spring l9 reacting upwardly against a nut threaded in the bore of the shell 2.

Another feature of this whereby to adjust the nut tion of pressure of the spring 19. means includes a wrench socket 2i to non-turnthe nut 29. A stem 22 extends up from the socket and has a drive key 23 turnable in the shell, to engage a stop 2A fixed therein, and having longitudinal movement limited by top and bottom stops 25 and 25 in the shell. To the upper end of the stem is attached a coupling 21 to join to a string in making up a tool assembly using this jar.

By lowering the tripped housing unit (shell and barrel) the tripping sleeve is again shifted down the stuck mandrel to again interlock the core lugs ist into the sleeve threads in readiness and jar function.

Enough clearance is left at C between the foot of the barrel 2?) and the bottom coupling 5 to allow the sleeve if! to open from its bearing washinvention is a means 20 at will for regula- The adjusting ers H so that liquid can flush out small solid particles which may collect in the tripping sleeve. A wash pipe [1 screws into the upper end of the mandrel.

Figure 1 shows the mandrel lugs Q1: in a position interlocked between the teeth l2, between the windows, of the sleeve It and therefore locking the shell and its hammer H in a position to make an up stroke toward the anvil A; the splines 6 being for turning torque only from the sleeve to the mandrel. When pulling tension is put on the shell and the barrel jar may be connected) the sleeve 19 is forced upward by the barrel and because of the inclination of the now engaged teeth l2 and the lugs 40: the sleeve exerts a strong turning torque on the frozen or stuck mandrel or its attached implement. Ihis-is a desired action as the sustained torque will aid in the jarring effect.

When the engaged cam lugs and cooperative teeth 12 can no longer resist the turning torque and the torque overcomes the spring pressure on the dog 9, the the dog upward and the released sleeve H3 moves its teeth 12 into register with the escapeways I3. The freed sleeve and the hammer barrel are now snapped upward along the mandrel and the hammer strikes the anvil. During the jar stroke the splineways 6 shift upward along the stationary splines 6. The right-hand pitch of the cam cam facet l5 of the sleeve forces superj acent tool 2b by the tool string (in which the teeth 4 l2 causes the sleeve to rotate to the left-hand (viewed looking down, Fig. 1)

What is claimed is:

1. A rotary jar, for well tools strings, having, in combination, an anvil-faced mandrel structure provided with peripheral camming lugs, a sleeve having internal, camming teeth in a row along the sleeve bore and which are complementary to the said lugs and an escape-way longitudinally in the sleeve for longitudinal shift of the sleeve when its teeth are freed from the said lugs, and a mandrel hammer housing in which the sleeve is rotative and axially movable; the housing, when under tension, operative to pull the sleeve teeth against the mandrel lugs whereby to effect a sliding trip-off of the sleeve from the lugs a tubular, sleeve-locking dog slidably splined on the mandrel, said dog and sleeve having cooperative, lateral, locking faces whereby the dog is repressed by the sleeve to permit free ascent of the housing as to the mandrel forhammer blow when the said lugs and teeth relatively turn out of engagement, an expansion spring seated on the upper end of the dog, a nut threaded in the housing and compressing the upper end of the spring onto the sleeve, and a socket wrench enclosed in the housing and shiftable to and from operative engagement with the said nut whereby to adjust the spring compression.

2. The jar of claim 1; and means in the housing for connecting the wrench to the said spring nut at any time desired when the jar is organized in a tool string.

3. The jar of claim 2; a wrench stem slidable and having a limited degree of rotation in the upper end of the housing and adapted to lock the socket onto said upper end of the nut and turn it in the housing to change compression of said spring; the wrench normally being disengaged from the nut.

4. In a tool string jar; a torque trip-off device, a housing for said device, a spring for controlling trip action of the device, and means for varying the spring compression at will and including a nut threaded in the housing and engaging one end of the spring, and a wrench freely shiftable and having less than one rotation in the housing to interlock with and turn the said nut by rotation of the housing; the wrench having a stemprovided with a shoulder on and by which the housing is suspendable and is rotative, said housing having a hammer part and telescoping on an anvil part of the mandrel to be jarred by the hammer.

' WILLIAM H. DUMBLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

